Welting cord and method of making same



Dec. 9, 1969 J. B. AMBROSE 3,482,483

WELTING CORD AND METHOD OF MAKING SAME Filed March 6, 1968 PRIOR ART) INVENTOR JERE B. AMBROSE ATTORNEYS United States Patent 3,482,483 WELTING CORD AND METHOD OF MAKING SAME Jere B. Ambrose, Birmingham, Mich., assignor to Northern Fiber Products Company, Birmingham, Mich.

Filed Mar. 6, 1968, Ser. No. 711,071 Int. Cl. D04c 1/12; D02g 3/36, 3/08 U.S. Cl. 876 4 Claims ABSTRACT OF THE DISCLOSURE Background of invention Welting cords, commonly used to form the welted seams on upholstered furniture, such as upholstered chairs, automobile seats and the like, have been made of a" core, surrounded by a wrapper, in turn held together with an open mesh braid. These welting cords are used as the fillers for the welted seam, that is, they are surrounded and covered with the fabric forming the upholstery along the seamed edges of the furniture.

In the prior art types of welting cords, the core has usually been made of a long strip of relatively hard paper which has been twisted into a tight, approximately circular in cross-section, rod-like shape. The core, after twisting into its shape, has been surrounded by a thin paper wrapper, after which the open braid, formed of fine threads, has been applied.

These welting cords have generally been wavy along their lengths, that is, not straight, and have been diflicult to straighten out while sewing a welted seam. In addition, it has been difficult to make them sufiiciently firm to form a good welted seam, and particularly, in turning corners, they have a tendency to buckle and flatten to some extent. Further, the step of twisting the core material has been a relatively time consuming and expensive step.

Summary of invention It is an object of this invention, to provide a welting cord which is firmer, straighter and which remains straighter, and is less costly than the prior welting cords.

I have discovered that by transversely crumpling a long sheet or strip used for making the core, so that parallel fold lines are formed running the length of the cord, the tendency of the cord to wave or kink is substantially eliminated. Moreover, this transverse crumpling permits the use of a thicker, pro-creped toweling type of paper which is harder and thicker than the types of papers previously used for the twisted cores and which could not practically be used before because of the inability to easily twist such paper without tearing, so that a much harder and firmer core may be produced. I have also discovered that by using my new form of core, that the wrapper, which is formed normally of a thin, cellulose type of wadding paper, may be embedded in and keyed to the core and if sufiicient wrapper layers are used, will still present a smooth outer surface so that the composite cord will easily corner or turn, forming seam 3,482,483 Patented Dec. 9, 1969 corners without buckling and yet with retaining its proper cross-sectional shape.

In summary, my invention contemplates forming a welting cord with a core of relatively thick, creped type of toweling paper which is transversely crumpled to form longitudinally extending fold lines, with the core then being surrounded by an inner wrapper layer embedded in and keyed between two folds, at least, of the core, with a surrounding layer which is relatively smooth and unbent, in turn surrounded by the conventional open mesh braid.

These and other objects and advantages of this invention will become apparent upon reading the following description, of which the attached drawings form a part.

Description of drawings Detailed description Referring first to FIG. 6, a short length of completed welting cord 10 is illustrated in perspective. The actual cord which is commercially used is of an overall diameter of approximately 7 of an inch, although it varies considerably above and below that amount depending upon the particular welted seam to be produced.

The cord comprises a core 11, a wrapper 12 and a surrounding, open mesh braid 13.

The core is formed of a long strip or ribbon 15 of a pre-creped toweling paper, as for example, a 28-32 pound by weight type paper characterized by a stretch of 56%, with tensile strength in its length direction of approximately ounces and in its transverse direction of about 50 ounces. This is a conventional, commercially available type of paper.

As shown by the arrows 16 and 17 in FIG. 2, the ribbon or strip 15 is crumpled transversely to form fold lines which run the length of the strip. Upon completion of the crumpling, an approximately circular in cross-section rod-like member is formed which is relatively tightly compressed and firm.

Next, as illustrated in FIG. 4, the wrapper is applied to the core, the wrapper being formed of a long ribbon or strip 18 of a light-weight cellulose wadding type of paper, such as for example, a 12 pound paper which, as illustrated in FIG. 5 is simply wrapped around the core in at least one and preferably two or three layers.

The inner layer of the wrapper is crinkled or bent during the wrapping process so that it embeds or is forced between at least two adjacent pair of core folds to form mechanical interlocking keys 19 (see FIG. 6) which extend the length of the cord. The outer layers of the wrapper present the conventional relatively smooth, unbent surface.

Following the application of the wrapper, the open mesh braid is applied using a conventional braiding machine and conventional braiding thread, such as rayon of 120 denier. The braid functions to maintain the cord in its shape, as is conventional.

FIG; 7 illustrates the prior art core 20 which had been formed by starting with a long strip or ribbon and then twisting it about its axis to form a twisted core rather than a folded or crumpled one as shown in FIG. 3.

The crumpled or folded core tends to maintain the cord straight in use and eliminates the objectionable waviness of the twisted type of core and in addition, with the keying of the wrapper to the core, there is a tendency to maintain not only straightness but also cross-sectional shape when bending around corners. In addition, the crumpling step can be accomplished much more rapidly and therefore, less expensively than the twisting of the prior art core, in addition to which, crumpling eliminates any tendency of the paper to tear as took place during the prior art twisting.

Having fully described an operative embodiment of this invention, I now claim:

1. In a welting cord comprising a paper core surrounded by a thin paper wrapper, in turn surrounded by an open mesh braid, formed of fine threads surrounding the wrapper and holding the wrapper and core in position; the improvement comprising:

said core consisting of a single elongated, narrow strip of relatively thick, pre-creped toweling paper which is transversely folded into numerous parallel fold lines extending the full length of and parallel to the axis of the core, and forming a relatively tight roughly circular in cross-section mass, with the paper strip and its fold lines being untwisted relative to the axis of the core.

2. In a welting cord as defined in claim 1, and including said wrapper forming at least two layers surrounding the core, with portions of the inner layer being 3 bent into and embedded between at least some of the core fold lines; and the outer wrapper layer being relatively smooth and unbent.

3. A method of forming a welting cord comprising a 4 thick, toweling paper, surrounded by a thin, cellulose wadding sheet, in turn surrounded by an open mesh braid of fine thread, comprising:

transversely folding the paper into numerous longitudinally directed parallel fold lines extending the full length of the strip while compressing the paper strip transversely into a tight mass and while holding the strip against twisting thereby forming a roughly circularly shaped, in cross-section, untwisted, straight core having numerous approximately parallel fold lines running the full length of and parallel to the axis of the core;

wrapping the core with at least one layer of the thin wadding sheet;

and forming the braid around the wrapped core to thereby hold the core and wrapper together in position.

4. A method as defined in claim 3, and including the steps of bending and embedding a portion of the wrapper layer between two adjacent core fold lines to thereby key the wrapper to the core, and surrounding said bent layer with at least another relatively smooth, unbent wrapper layer.

References Cited UNITED STATES PATENTS 2,465,081 3/1949 Fleischer 87-6 2,503,791 4/1950 Boersma 87-6 2,557,343 6/1951 Cook 87-1 2,722,861 11/1965 Francis 87---1 2,724,431 11/ 1955 Boersma 87-6 XR 2,741,149 4/ 1956 Francis 87--1 2,979,982 4/ 1961 Weitzel 87-6 3,089,379 5/1963 Finor et al 87--1 XR JOHN PETRAKES, Primary Examiner US. Cl. X.R. 57144, 151; 87--7 

